If you can find the weaknesses in your home security, a skilled thief will definitely be able to. That's why Brett and Kate McKay at The Art of Manliness recommend you "case your joint", or scope out how you would break in to your own home:

Are there areas around my home that would offer cover for a bad guy to break in without being seen?

Is my house well-lit at night?

Do I have any unlocked doors or windows?

Can I easily see valuables in my home from the street?

Do the people in my home have routines that would make it easy for a burglar to figure out when would be the best time to hit my house?

Be honest and do your best to think the way a burglar would. How would you break into your house? As the McKay's note, the keys to a good theft are time, noise, and visibility, so consider those elements as you case your joint. Pretend to plan a break in during the day and night to make sure you have everything covered. Have some fun with it and fix any found weaknesses as soon as you can.

Comments

Like most security, the simplest tactic is to avoid being an easy or enticing prospect. The majority of burglars (at least where I live) are motivated by drugs. So they just want a soft target and cash or easily saleable items.

So, in addition to the suggestions above, basic things like:
1. Have fences all round that are high or spiky enough not to be easily climbed over
2. Have a visible alarm box on the house (even if it's not functional)
3. Put a "Rottweiler Lives Here" or equivalent sign on the front fence
4. Not having multiple CCTV cameras visible (hallmark of a drug dealer or lab)
5. If you run a business from home, have a "No cash kept on premises" sign

will deter most.

However, if someone is truly motivated to break in, they will. The more "professional" thieves will do research, reconnaissance and bypass any security. For them, the best avoidance is to keep high-end stuff in a safety deposit box instead. Again, don't be appealing and hope they look elsewhere.